1. Basic Information
concept
valve seal
(Valve stem seal) generally consists of an outer skeleton together and vulcanized fluororubber, loaded from the mouth portion diameter energizing spring or wire, the engine valve for sealing the guide rod, is an oil seal.
can prevent the oil from entering into the exhaust pipe, resulting in the loss of oil, a mixed gas of gasoline and air to prevent the leakage of exhaust gas and prevent the engine oil into the combustion chamber. Valve seal is one of the important parts of the engine valve train, in contact with the petrol and oil at an elevated temperature. Therefore need excellent heat resistance and oil resistance material, typically made of rubber is fluorine.
valve seal structure diagram: see below
The installation and replacement of the valve seals
(1) the valve stem seal removal steps:
Removal of the camshaft and ① hydraulic tappets, and stores it face down, it should be noted tappet not interchangeable operation. Removing plug with a spark plug wrench 3122B, the top dead center of the piston raised to a corresponding cylinder, the pressure in the hose VW653 / 3 of the spark plug is screwed into the threaded hole.
② bolt compresses the spring 3362 is attached to the tool head, as shown in (1). Adjusted to the correct position related valve, then a pressure hose connected to the air compressor (an air pressure of at least 600kPa). A threaded thrust member and the mandrel is pressed down the valve spring, remove the spring.
③ may tap the gas lock valve spring retainer block removed. Tool valve stem seal 3364 is pulled out, as shown in (2).
(2) of the valve stem seal installed.
The plastic sleeve (A in FIG. (3)) is attached to the valve stem, the valve stem to prevent damage to the new seal. In the oil seal lip Kouqing coated with a layer of oil. The seal (FIG. (3) in B) is mounted on the tool 3365, then slowly pushed onto the valve guide. Special note: the installation into the exhaust in front of, to be coated with a layer of oil on the valve stem. The reason valve seal aging
If your car is the car accelerated weakness or blue smoke, then state your valve seal has been aging. So what causes this series of problem is it?
First, the valve seal installation: for exampleWhen installation is mixed, inside the pipe or foreign matter, dust, causing leakage into the seal; poor seal assembly caused by leakage caused damage; cause leakage seal mounted in the wrong direction or because of uneven coating process, the coating material into the sealing layer.
followed by selection sealing problems: due to the pressure caused by excessive gap bites, and then after mixed with air, burning adiabatic compression causes the seal; High Frequency Reciprocating motion causes the seal heat, dry grinding; environmental dust seal caused by abnormal wear ; sealed trench rust cause leakage problems and the like.
again the problem is the design of the sealing equipment. This includes
1, the support member material selection guide improper damage the cylinder rod
2, inappropriate friction gap, resulting in a gap extrusion bite
3, the cylinder piston cylinder end portion of the thread improper lead angle, damage seals
4, the lead angle improper seal mounting ring injury
5, the sliding surface roughness inappropriate seal wear
6, non-uniform plating, the opening through the upper surface of the sealing holes, scratches wear ring
7, in particular the sealing groove of the shaft seal groove enough roughness, wear damage to the sealing member
is the final product itself may be a problem, or the problem is sealed and stored, shipped by high temperature, causing deterioration of the sealing material, is deteriorated.